Section 300.913 - Monitoring the use of dispersantsThe responsible party shall monitor any subsurface use of dispersant in response to an oil discharge, any surface use of dispersant for more than 96 hours after initial application in response to an oil discharge, and any surface use of dispersant in response to oil discharges of more than 100,000 U.S. gallons occurring within a 24-hour period, and shall submit a Dispersant Monitoring Quality Assurance Project Plan (DMQAPP) covering the collection of environmental data within this section to the OSC. When any dispersant is used subsurface in response to an oil discharge, the responsible party shall implement paragraphs (a) through (g) of this section for the entire duration of the subsurface dispersant use. When any dispersant is used on the surface in response to oil discharges of greater than 100,000 U.S. gallons occurring within a 24-hour period, the responsible party shall implement paragraphs (a) through (g) of this section as soon as possible for the entire or remaining duration of surface dispersant use, as applicable. When any dispersant is used on the surface in response to an oil discharge for more than 96 hours after initial application, the responsible party shall implement paragraphs (a) through (g) of this section for the remaining duration of surface dispersant use.
(a) Document: (1) The characteristics of the source oil.(2) The best estimate of the oil discharge volume or flow rate, periodically reevaluated as conditions dictate, including a description of the method, associated uncertainties, and materials.(3) The dispersant used, rationale for dispersant choice(s) including the results of any efficacy and toxicity tests specific to area or site conditions, recommended dispersant-to-oil ratio (DOR).(4) The application method(s) and procedures, including a description of the equipment to be used, hourly application rates, capacities, and total amount of dispersant.(5) For subsurface discharges, the best estimate of the discharge flow rate of any associated volatile petroleum hydrocarbons, periodically reevaluated as conditions dictate, including a description of the method, associated uncertainties, and materials.(b) Collect a representative set of ambient background water column samples in areas not affected by the discharge of oil, at the closest safe distance from the discharge as determined by the OSC, and in all directions of likely oil transport considering surface and subsurface currents. Collect a representative set of baseline water column samples absent dispersant application at such depths and locations affected by the oil discharge, considering surface and subsurface currents, oil properties, and other relevant discharge conditions. On a daily basis, collect dispersed oil plume water column samples at such depths and locations where dispersed oil is likely to be present, considering surface and subsurface currents, oil properties, and other relevant discharge conditions. Collect these ambient background, baseline, and dispersed oil plume water column samples following standard operating and quality assurance procedures. Analyze the collected ambient background, baseline, and dispersed oil plume water column samples for:(1) In-situ oil droplet size distribution, including mass or volume mean diameter for droplet sizes ranging from 2.5 to 2,000 [MICRO]m, with the majority of data collected between the 2.5 and 100 [MICRO]m size.(2) In-situ fluorometry and fluorescence signatures targeted to the type of oil discharged and referenced against the source oil.(3) Dissolved oxygen (DO) (subsurface only).(4) Total petroleum hydrocarbons, individual resolvable constituents including volatile organic compounds, aliphatic hydrocarbons, monocyclic, polycyclic, and other aromatic hydrocarbons including alkylated homologs, and hopane and sterane biomarker compounds.(5) Methane, if present (subsurface only).(6) Heavy metals, including nickel and vanadium.(c) Considering available technologies, characterize the dispersant effectiveness and oil distribution including trajectory, accounting for the condition of oil, dispersant, and dispersed oil components from the discharge location, and describing associated uncertainties.(d) Characterize the ecological receptors (e.g., aquatic species, wildlife, and/or other biological resources) and their habitats that may be present in the discharge area and their exposure pathways. The characterization shall include, but is not limited to, those species that may be in sensitive life stages, transient or migratory species, breeding or breeding-related activities (e.g., embryo and larvae development), and threatened and/or endangered species that may be exposed to the oil that is not dispersed, the dispersed oil, and the dispersant alone. The responsible party shall also estimate an acute toxicity level of concern for the dispersed oil using available dose-response information relevant to potentially exposed species following a species sensitivity distribution.(e) Immediately report to the OSC any: (1) Deviation of more than 10 percent from the mean hourly dispersant use rate for subsurface application, based on the dispersant volume authorized for 24 hours use, and the reason for the deviation.(2) Ecological receptors of environmental importance, and any other ecological receptors as identified by the OSC or the Natural Resource Trustees, including any threatened or endangered species that may be exposed based on dispersed plume trajectory modeling and level of concern information.(f) Report daily to the OSC water sampling and data analyses collected in paragraph (b) of this section and include: (1) For each application platform, the actual amount of dispersant used for each one-hour period and the total amount of dispersant used for the previous 24-hour reporting period.(2) All collected data and analyses of those data within a time frame necessary to make operational decisions (e.g., within 24 hours of collection), including documented observations, photographs, video, and any other information related to dispersant use, unless an alternate time frame is authorized by the OSC.(3) For analyses that take more than 24 hours due to analytical methods, provide such data and results as available but no later than five days, unless an alternate time frame is authorized by the OSC.(4) Estimates of the daily transport of dispersed oil, non-dispersed oil, the associated volatile petroleum hydrocarbons, and dispersants, using available technology as described in paragraph (c) of this section.(g) Report all information provided to the OSC under paragraphs (e) and (f) of this section to the applicable RRT(s). 86 FR 40263 , July 27, 2021